Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751576AbdGRJi1 (ORCPT ); Tue, 18 Jul 2017 05:38:27 -0400 Received: from mail-lf0-f47.google.com ([209.85.215.47]:35343 "EHLO mail-lf0-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751413AbdGRJiY (ORCPT ); Tue, 18 Jul 2017 05:38:24 -0400 Subject: Re: [PATCH v3 3/5] pwm-backlight: add support for PWM delays proprieties. To: Enric Balletbo i Serra , Thierry Reding , Lee Jones , Jingoo Han , Bartlomiej Zolnierkiewicz , Rob Herring , Pavel Machek , Richard Purdie , Jacek Anaszewski , Heiko Stuebner Cc: linux-pwm@vger.kernel.org, linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org, groeck@chromium.org, linux-rockchip@lists.infradead.org References: <20170717212811.25374-1-enric.balletbo@collabora.com> <20170717212811.25374-3-enric.balletbo@collabora.com> From: Daniel Thompson Message-ID: Date: Tue, 18 Jul 2017 10:38:19 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.1 MIME-Version: 1.0 In-Reply-To: <20170717212811.25374-3-enric.balletbo@collabora.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3558 Lines: 100 On 17/07/17 22:28, Enric Balletbo i Serra wrote: > Some panels (i.e. N116BGE-L41), in their power sequence specifications, > request a delay between set the PWM signal and enable the backlight and > between clear the PWM signal and disable the backlight. Add support for > the new post-pwm-on-delay-us and pwm-off-delay-us proprieties to meet > the timings. > > Signed-off-by: Enric Balletbo i Serra > --- > Changes since v2: > - Move the pwm/enable sequence to another patch (Thierry Reding) > Changes since v1: > - As suggested by Daniel Thompson > - Do not assume power-on delay and power-off delay will be the same > - Move the check of dt property to the parse dt function. > > drivers/video/backlight/pwm_bl.c | 17 +++++++++++++++++ > include/linux/pwm_backlight.h | 1 + > 2 files changed, 18 insertions(+) > > diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c > index 909a686..528155d 100644 > --- a/drivers/video/backlight/pwm_bl.c > +++ b/drivers/video/backlight/pwm_bl.c > @@ -10,6 +10,7 @@ > * published by the Free Software Foundation. > */ > > +#include > #include > #include > #include > @@ -35,6 +36,7 @@ struct pwm_bl_data { > struct gpio_desc *enable_gpio; > unsigned int scale; > bool legacy; > + unsigned int pwm_delay[2]; Two named members would be better here (eliminating the "magic" 0 and 1). > int (*notify)(struct device *, > int brightness); > void (*notify_after)(struct device *, > @@ -56,6 +58,9 @@ static void pwm_backlight_power_on(struct pwm_bl_data *pb, int brightness) > > pwm_enable(pb->pwm); > > + if (pb->pwm_delay[0]) > + usleep_range(pb->pwm_delay[0], pb->pwm_delay[0] * 2); > + > if (pb->enable_gpio) > gpiod_set_value_cansleep(pb->enable_gpio, 1); > > @@ -70,6 +75,9 @@ static void pwm_backlight_power_off(struct pwm_bl_data *pb) > if (pb->enable_gpio) > gpiod_set_value_cansleep(pb->enable_gpio, 0); > > + if (pb->pwm_delay[1]) > + usleep_range(pb->pwm_delay[1], pb->pwm_delay[1] * 2); > + > pwm_config(pb->pwm, 0, pb->period); > pwm_disable(pb->pwm); > > @@ -175,6 +183,14 @@ static int pwm_backlight_parse_dt(struct device *dev, > data->max_brightness--; > } > > + /* > + * These values are optional and set as 0 by default, the out values > + * are modified only if a valid u32 value can be decoded. > + */ > + of_property_read_u32(node, "post-pwm-on-delay-us", > + &data->pwm_delay[0]); > + of_property_read_u32(node, "pwm-off-delay-us", &data->pwm_delay[1]); > + > data->enable_gpio = -EINVAL; > return 0; > } > @@ -273,6 +289,7 @@ static int pwm_backlight_probe(struct platform_device *pdev) > pb->exit = data->exit; > pb->dev = &pdev->dev; > pb->enabled = false; > + memcpy(pb->pwm_delay, data->pwm_delay, sizeof(pb->pwm_delay)); > > pb->enable_gpio = devm_gpiod_get_optional(&pdev->dev, "enable", > GPIOD_ASIS); > diff --git a/include/linux/pwm_backlight.h b/include/linux/pwm_backlight.h > index efdd922..bf37131 100644 > --- a/include/linux/pwm_backlight.h > +++ b/include/linux/pwm_backlight.h > @@ -13,6 +13,7 @@ struct platform_pwm_backlight_data { > unsigned int lth_brightness; > unsigned int pwm_period_ns; > unsigned int *levels; > + unsigned int pwm_delay[2]; > /* TODO remove once all users are switched to gpiod_* API */ > int enable_gpio; > int (*init)(struct device *dev); >